> FWIW, I make a point of _not_ registering at sites that require me to > remember yet another user ID and password. Which means that I was > looking at your work through a figurative peephole - which (for me) made > understanding as difficult as it could be made. I don't blame this on > you, but it's something you might take into consideration.

Those miniature pictures were a turn off for me.
If they were big enough to be able to see something, I might have been
interested enough to sign up for free, with a throw away account I would
never use again. But nonsense like that annoys me.

--
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

Posted by gaiatechnician on November 20, 2009, 7:20 pm

On Nov 20, 1:04am, d...@27.usenet.us.com wrote:

> > FWIW, I make a point of _not_ registering at sites that require me to> > remember yet another user ID and password. Which means that I was> > looking at your work through a figurative peephole - which (for me) made> > understanding as difficult as it could be made. I don't blame this on> > you, but it's something you might take into consideration.> Those miniature pictures were a turn off for me.> If they were big enough to be able to see something, I might have been> interested enough to sign up for free, with a throw away account I would> never use again. But nonsense like that annoys me.> --> Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

I did not know they required people to register now. You click on the
miniature pictures to enlarge them.
It used to be that anyone could see what was there. That was why I
joined.

Posted by dow on November 20, 2009, 4:02 pm

.

> The important part for me was "The video shows something resembling an> old Victrola audio horn that focuses varying light angles to a focal> point, some with multiple bounces.> -- Clarence A Dold - Hidden Valley Lake, CA, USA "

The problem with "horn" or "funnel" solar collectors is that only a
small fraction of the light that falls on the wide end finds its way
out of the narrow end. If you trace the paths of light rays going unto
a funnel, you'll see that most of them end up being bounced out of the
wide end. Also, of course, multiple reflections cause a lot of light
to be absorbed by inefficiencies of the mirror.

If you don't like parabolic reflectors, I suggest you try a completely
different approach. Blacken your cooking pot, and put an inverted
glass bowl over it to act as a greenhouse. Try to use a bowl that is
only slightly bigger than the pot. Even without any reflectors to
concentrate sunlight, the pot in the greenhouse can get hot enough to
boil water or cook food.

dow

Posted by gaiatechnician on November 20, 2009, 7:30 pm

> .> > The important part for me was "The video shows something resembling an> > old Victrola audio horn that focuses varying light angles to a focal> > point, some with multiple bounces.> > -- Clarence A Dold - Hidden Valley Lake, CA, USA "> The problem with "horn" or "funnel" solar collectors is that only a> small fraction of the light that falls on the wide end finds its way> out of the narrow end. If you trace the paths of light rays going unto> a funnel, you'll see that most of them end up being bounced out of the> wide end. Also, of course, multiple reflections cause a lot of light> to be absorbed by inefficiencies of the mirror.> If you don't like parabolic reflectors, I suggest you try a completely> different approach. Blacken your cooking pot, and put an inverted> glass bowl over it to act as a greenhouse. Try to use a bowl that is> only slightly bigger than the pot. Even without any reflectors to> concentrate sunlight, the pot in the greenhouse can get hot enough to> boil water or cook food.> dow

I agree on the multible bounces. I have not finished my model yet but
so far everything is bouncing to hit the target in the 2 hour time
period. I have not been tracing the light path, I have used a laser
pointer to make the path.
The horn shape may be difficult or impossible for an amateur like me
to make but I am sure they could be stamped out very easily in a
factory.
Brian

Posted by gaiatechnician on November 20, 2009, 9:04 pm

http://en.wikipedia.org/wiki/Holmdel_Horn_Antenna
I think the picture there might help.
For solar, maybe as extra input to the sides of a box cooker, I think
it has potential.
Especially if it is inputed near the bottom.
Also, note that in a solar collector situation, the curve will be
different because it might be designed to catch 30 degrees or so of
sun movement. You can constrain the design just to catch light from a
30 or 50 degree segment or whatever degrees of the sky if you wish. (I
think that is a sensible thing to do).
I know by now that most are not interested so I shall let it be.